en.wikipedia.org/wiki/Physics_of_the_Impossible
3 corrections found
In 1988, researchers first teleported information at the quantum level.
This date is wrong. Quantum teleportation was proposed in 1993 and first demonstrated experimentally in 1997, not 1988.
Full reasoning
Standard histories of quantum teleportation place the idea in 1993 and the first experiments in 1997.
- Nature Reviews Physics states: "The idea of quantum teleportation was proposed in 1993 and put into practice in 1997 by two experimental groups."
- The 1997 Nature paper "Experimental quantum teleportation" says quantum teleportation "is demonstrated experimentally" and is published on December 1, 1997.
So the article's claim that researchers first teleported quantum information in 1988 is inconsistent with the standard published timeline by at least five years for the proposal and nine years for the first experiment.
2 sources
- 25 years of experimental quantum teleportation | Nature Reviews Physics
The idea of quantum teleportation was proposed in 1993 and put into practice in 1997 by two experimental groups.
- Experimental quantum teleportation | Nature
Article Published: 01 December 1997 ... Quantum teleportation ... is demonstrated experimentally.
Albert Einstein showed that black holes could not exist.
This overstates and misstates Einstein's role. Black holes are a prediction of general relativity, and Einstein's later 1939 argument against their physical formation is now understood to have been mistaken.
Full reasoning
This sentence is inaccurate in two ways.
First, black holes are a prediction of Einstein's general theory of relativity, not something his work ruled out. NASA's black-hole explainer says black holes are real cosmic objects studied through their effects and describes them as dense objects with an event horizon from which light cannot escape.
Second, while Einstein did publish a 1939 paper arguing that physical processes would prevent the formation of what he called the "Schwarzschild singularity," historians of physics note that this argument was mistaken. John D. Norton (University of Pittsburgh) explains that Einstein treated the event horizon as a physical singularity because of the coordinates he used, whereas modern relativity recognizes that as a coordinate artifact, not proof that black holes cannot exist.
So it is not correct to say Einstein "showed" black holes could not exist. At most, he argued against their physical formation in one 1939 paper, and that argument did not hold up.
2 sources
- Black Holes - NASA Science
Black holes are among the most mysterious cosmic objects, much studied but not fully understood... A black hole is so dense that gravity just beneath its surface, the event horizon, is strong enough that nothing - not even light - can escape.
- Einstein on Black Holes
In 1939, Einstein published a paper in which he argued that physical processes would prevent the formation of black holes... We now recognize that these singularities are merely artifacts of the particular coordinate systems used by Einstein and not physical pathologies.
In 2008, two groups, one at Caltech and the other at Karlsruhe Institute of Technology, bent red light and blue-green of the visible spectrum.
This mixes up the institutions and dates. Caltech's blue-green visible-light result was reported in 2007, the 2008 red-light work was from UC Berkeley, and KIT's visible-light cloak was reported in 2011.
Full reasoning
The sentence combines separate metamaterials milestones incorrectly.
- Caltech reported negative refraction in the blue-green visible spectrum on March 22, 2007, not 2008.
- The widely reported 2008 red-light bulk metamaterial result was from UC Berkeley, whose researchers said they observed negative refraction from red light wavelengths as short as 660 nanometers.
- KIT says its team presented a first 3D cloak in 2010 for 1500–2600 nm wavelengths (infrared, not visible), and only in 2011 produced a 3D invisibility cloak for visible light at 700 nm (red).
So the article's wording is wrong on both the date and the institution for these visible-light demonstrations.
3 sources
- Negative Refraction of Visible Light Demonstrated; Could Lead to Cloaking Devices - Caltech
March 22, 2007 ... constructing a nanofabricated photonic material that creates a negative index of refraction in the blue-green region of the visible spectrum.
- Invisibility shields one step closer with new metamaterials that bend light backwards - UC Berkeley
By Sarah Yang, Media Relations | 11 August 2008 ... The authors of the Science paper observed negative refraction from red light wavelengths as short as 660 nanometers.
- Karlsruhe Invisibility Cloak - Disappearing Visibly - KIT
Last year, the Wegener team presented the first 3D invisibility cloak... for wavelengths from 1500 to 2600 nm... In the past year ... producing the first 3D invisibility cloak for unpolarized visible light in the range of 700 nm.